Refastenable fastening devices of the hook and loop type are currently used widely in a great number of situations. Such refastenable fastening devices have been particularly useful in clothing, disposable absorbent articles, and the like. Such devices are used when it is desirable to create a refastenable bond between two or more articles or between several surfaces of the same article. In certain applications, these refastenable fastening devices have replaced conventional buckles, zippers, buttons, snaps, tie fasteners, and sewing.
A popular type of mechanical fastener currently in wide use which utilizes mechanical entanglement to create a refastenable bond is sold under the trademark "VELCRO". VELCRO fastening devices are described in greater detail in U.S. Pat. No. 2,717,437, U.S. Pat. No. 3,009,235, U.S. Pat. No. 3,266,113, U.S. Pat. No. 3,550,837, U.S. Pat. No. 4,169,303, and U.S. Pat. No. 4,984,339.
VELCRO fasteners utilize two components. A male component and a female component. The male and female components are often referred to as the hook and loop components, respectively. The male component contains a plurality of resilient, upstanding hook shaped elements. The female component of the fastening device generally consists of a fabric containing a plurality of upstanding loops on its surface. When the male component and the loop component are pressed together in a face to face relationship to close the fastening device, the hooks entangle the loops forming a plurality of mechanical bonds between the individual hooks and loops. When these bonds have been created, the components will not generally disengage under normal conditions. This is because it is very difficult to separate the components by attempting to disengage all the hooks at once. However, when a gradual peeling force is applied to the components, disengagement can be easily effected. Under a peeling force, since the hooks are comprised of a resilient material, they will readily open to release the loops.
This type of fastening device has been found especially useful on disposable articles such as disposable garments, disposable diapers, disposable packages, cartons, and the like. Such fastening devices provide a secure closing means. However, the use of existing fastening devices of this type on disposable articles has been limited due to the fact that such fastening devices are relatively costly. A major reason that such fastening devices are costly is that they have high manufacturing costs. These high manufacturing costs are associated with both the hook and loop components of these devices.
Conventional hook and loop components are typically formed by making a fabric with a number of woven loops extending outwardly from a backing. The loops may be provided by weaving a base fabric containing supplementary threads to form the loops, or by knitting the loops into a fabric. In other hook and loop components, the loops may be formed by pleating or corrugating processes. The male components of such fastening devices are typically formed by subsequently cutting the loops. The cut loops serve as the hooks of the male component.
These processes generally produce costly hook and loop fastening materials because they are relatively slow. The hook and loop components of such fastening devices are also usually made out of the same relatively expensive material. This material is relatively expensive because the material used in the male component needs to be resilient so that the hooks can disengage from the loop component when the device is open.
Several attempts have been made to make alternative types of female components for fastening devices. However, such attempts have generally suffered from a number of drawbacks.
U.S. Pat. No. 3,694,867 issued to Stumpf on Oct. 3, 1972, discloses a "separable clasp" having a female component that comprises a "high loft" nonwoven fabric and a backing layer of consolidated flexible adhesive. However, the loop component disclosed in the Stumpf patent is prepared by performing the steps of: (1) activating an open pattern adhesive in which the fibers are imbedded, (2) consolidating the adhesive into a substantially continuous backing layer, and (3) simultaneously looping portions of the fibers such that the fibers form individual loops that extend outwardly from the backing. The female component disclosed in this patent suffers from the drawback that it is made by processes that involves mechanically manipulating fibers in the form of loops. Thus, the female components described therein do not appear to be significantly less expensive to manufacture than conventional loop components.
U.S. Pat. No. 3,708,833 issued to Ribich, et al. on Jan. 9, 1973, discloses a refastenable fastening device having a female component that comprises reticulated urethane foam secured to a backing layer. The female component disclosed in the Ribich, et al. patent suffers from the drawback that foams typically do not have enough openings for the hooks of conventional male components to penetrate. In addition, reticulated foam generally does not have sufficient strength to hold such hooks when forces are applied to the fastening device. Further, manufacturing reticulated foam is a relatively expensive process.
U.S. Pat. No. 4,761,318 issued to Ott, et al. on Aug. 2, 1988, discloses a loop fastener that can contemporaneously be both formed and also attached to a substrate without the need for any additional steps such as sewing or utilizing pressure sensitive adhesives to affix it to the substrate. However, the Ott loop fastener comprises a fibrous structure having a multiplicity of loops that is adhered to a layer of thermoplastic resin. Thus, the process disclosed in this patent suffers from the drawback that heat must be applied to bond the fibrous structure to the backing.
U.S. Pat. No. 5,032,122 issued to Noel, et al. on Jul. 16, 1991, discloses a loop fastening material having a backing of orientable material and a multiplicity of fibrous elements extending from the backing. The fibers are secured to the backing while the backing is in a dimensionally unstable state. The backing is then caused to be transformed to its dimensionally stable state thereby shearing the fibrous elements to form the catching regions of the loop material. Although the Noel patent discloses an acceptable low cost loop fastening material, the search has continued for more economical loop fastening materials and methods for producing such materials.
U.S. Pat. No. 5,318,555 issued to Siebers, et al. on Jun. 7, 1994 discloses an absorbent article having a fastening system comprising a plurality of hook members attached to one portion of the article and a plurality of loop members attached to a loop panel wherein the loop panel may be intermittently attached to the article. However, the Siebers, et al. patent focuses on the means of attaching a loop panel to an absorbent article rather than on an improved loop material itself.
Thus, it is an object of the present invention to provide an improved fastening device for disposable articles.
It is another object of the present invention to provide an improved female component of a refastenable hook and loop type fastening device.
It is a further object of the present invention to provide a female component for a hook and loop type fastening device which may be formed by joining a plurality of filaments on an elastomeric backing without manipulating the fibers into the form of loops to form a low cost loop fastening material.
It is another object of the present invention to provide a female component for a fastening device that can be used with both commercially available male components having resilient individual hooks, as well as less expensive male components with more brittle hooks than those currently in use.
These and other objects of the present invention will be more readily apparent when considered in reference to the following description and when taken in connection with the accompanying drawings.